Merge pull request #87 from phantomphildius/page-count

Add page_count when using Paginators

README.md

@@ -464,6 +464,9 @@ JSONAPI.configure do |config|
   config.top_level_meta_include_record_count = true
   config.top_level_meta_record_count_key = :record_count
 
+  config.top_level_meta_include_page_count = true
+  config.top_level_meta_page_count_key = :page_count
+
   config.use_text_errors = false
 
   config.exception_class_whitelist = []

lib/jsonapi/utils/response/formatters.rb

@@ -194,6 +194,10 @@ def result_options(records, options)
             if JSONAPI.configuration.top_level_meta_include_record_count
               data[:record_count] = record_count_for(records, options)
             end
+
+            if JSONAPI.configuration.top_level_meta_include_page_count
+              data[:page_count] = page_count_for(data[:record_count])
+            end
           end
         end
 

lib/jsonapi/utils/support/pagination.rb

@@ -157,6 +157,23 @@ def count_records(records, options)
           end
         end
 
+        # Count pages in order to build a proper pagination and to fill up the "page_count" response's member.
+        #
+        # @param record_count [Integer] number of records
+        #   e.g.: 42
+        #
+        # @return [Integer]
+        #   e.g 5
+        #
+        # @api private
+        def page_count_for(record_count)
+          return 0 if record_count.to_i < 1
+
+          size = (page_params['size'] || page_params['limit']).to_i
+          size = JSONAPI.configuration.default_page_size unless size.nonzero?
+          (record_count.to_f / size).ceil
+        end
+
         # Count records from the datatase applying the given request filters
         # and skipping things like eager loading, grouping and sorting.
         #

spec/controllers/posts_controller_spec.rb

@@ -94,6 +94,7 @@
           expect(data.size).to eq(2)
           expect(response).to have_meta_record_count(4)
 
+          expect(json.dig('meta', 'page_count')).to be(2)
           expect(json.dig('links', 'first')).to be_present
           expect(json.dig('links', 'next')).to be_present
           expect(json.dig('links', 'last')).to be_present
@@ -109,6 +110,7 @@
             expect(data.size).to eq(1)
             expect(response).to have_meta_record_count(4)
 
+            expect(json.dig('meta', 'page_count')).to be(4)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'prev')).to be_present
             expect(json.dig('links', 'next')).to be_present
@@ -126,6 +128,7 @@
 
             expect(data.size).to eq(1)
 
+            expect(json.dig('meta', 'page_count')).to be(4)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'prev')).to be_present
             expect(json.dig('links', 'next')).not_to be_present
@@ -142,6 +145,7 @@
             expect(subject).to have_http_status :ok
             expect(subject).to have_meta_record_count(4)
             expect(data.size).to be <= JSONAPI.configuration.default_page_size
+            expect(json.dig('meta', 'page_count')).to be(1)
           end
         end
       end

spec/controllers/users_controller_spec.rb

@@ -113,6 +113,7 @@
             expect(data.size).to eq(2)
             expect(response).to have_meta_record_count(3)
 
+            expect(json.dig('meta', 'page_count')).to eq(2)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'next')).to be_present
             expect(json.dig('links', 'last')).to be_present
@@ -128,6 +129,7 @@
             expect(data.size).to eq(1)
             expect(response).to have_meta_record_count(User.count)
 
+            expect(json.dig('meta', 'page_count')).to eq(3)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'prev')).to be_present
             expect(json.dig('links', 'next')).to be_present
@@ -144,6 +146,7 @@
             expect(data.size).to eq(1)
             expect(response).to have_meta_record_count(User.count)
 
+            expect(json.dig('meta', 'page_count')).to eq(3)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'prev')).to be_present
             expect(json.dig('links', 'last')).to be_present
@@ -162,6 +165,7 @@
             expect(data.size).to eq(1)
             expect(response).to have_meta_record_count(count)
 
+            expect(json.dig('meta', 'page_count')).to eq(1)
             expect(data.dig(0, 'attributes', 'full_name')).to eq(user.full_name)
           end
         end
@@ -172,6 +176,7 @@
             expect(response).to have_http_status :ok
             expect(data.size).to be <= JSONAPI.configuration.default_page_size
             expect(response).to have_meta_record_count(User.count)
+            expect(json.dig('meta', 'page_count')).to eq(1)
           end
         end
       end
@@ -190,6 +195,7 @@
             expect(data.size).to eq(2)
             expect(response).to have_meta_record_count(User.count)
 
+            expect(json.dig('meta', 'page_count')).to eq(2)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'next')).to be_present
             expect(json.dig('links', 'last')).to be_present
@@ -205,6 +211,7 @@
             expect(data.size).to eq(1)
             expect(response).to have_meta_record_count(User.count)
 
+            expect(json.dig('meta', 'page_count')).to eq(3)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'prev')).to be_present
             expect(json.dig('links', 'next')).to be_present
@@ -221,6 +228,7 @@
             expect(data.size).to eq(1)
             expect(response).to have_meta_record_count(User.count)
 
+            expect(json.dig('meta', 'page_count')).to eq(3)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'prev')).to be_present
             expect(json.dig('links', 'last')).to be_present
@@ -233,6 +241,7 @@
             expect(response).to have_http_status :ok
             expect(data.size).to be <= JSONAPI.configuration.default_page_size
             expect(response).to have_meta_record_count(User.count)
+            expect(json.dig('meta', 'page_count')).to eq(1)
           end
         end
       end
@@ -251,6 +260,7 @@
             expect(data.size).to eq(2)
             expect(response).to have_meta_record_count(User.count)
 
+            expect(json.dig('meta', 'page_count')).to eq(2)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'next')).to be_present
             expect(json.dig('links', 'last')).to be_present
@@ -266,6 +276,7 @@
             expect(data.size).to eq(1)
             expect(response).to have_meta_record_count(User.count)
 
+            expect(json.dig('meta', 'page_count')).to eq(3)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'prev')).to be_present
             expect(json.dig('links', 'next')).to be_present
@@ -282,6 +293,7 @@
             expect(data.size).to eq(1)
             expect(response).to have_meta_record_count(User.count)
 
+            expect(json.dig('meta', 'page_count')).to eq(3)
             expect(json.dig('links', 'first')).to be_present
             expect(json.dig('links', 'prev')).to be_present
             expect(json.dig('links', 'last')).to be_present
@@ -294,6 +306,7 @@
             expect(response).to have_http_status :ok
             expect(data.size).to be <= JSONAPI.configuration.default_page_size
             expect(response).to have_meta_record_count(User.count)
+            expect(json.dig('meta', 'page_count')).to eq(1)
           end
         end
       end

spec/features/page_count_spec.rb

@@ -0,0 +1,91 @@
+require 'rails_helper'
+
+##
+# Configs
+##
+
+# Resource
+class PageCountTestResource < JSONAPI::Resource; end
+
+# Controller
+class PageCountTestController < BaseController
+  def index
+    jsonapi_render json: User.all, options: { resource: UserResource }
+  end
+end
+
+# Routes
+def TestApp.draw_page_count_test_routes
+  JSONAPI.configuration.json_key_format = :underscored_key
+
+  TestApp.routes.draw do
+    controller :page_count_test do
+      get :index
+    end
+  end
+end
+
+##
+# Feature Tests
+##
+
+
+describe PageCountTestController, type: :controller do
+  include_context 'JSON API headers'
+
+  before(:all) do
+    TestApp.draw_page_count_test_routes
+    FactoryGirl.create_list(:user, 3, :with_posts)
+  end
+
+  describe 'page count with a paged paginator' do
+    it 'returns the correct count' do
+      JSONAPI.configuration.default_paginator = :paged
+
+      get :index, params: { page: { size: 2, number: 1 } }
+
+      expect(json.dig('meta', 'page_count')).to eq(2)
+    end
+  end
+
+  describe 'page count with an offset paginator' do
+    it 'returns the correct count' do
+      JSONAPI.configuration.default_paginator = :offset
+
+      get :index, params: { page: { limit: 2, offset: 1 } }
+
+      expect(json.dig('meta', 'page_count')).to eq(2)
+    end
+  end
+
+  describe 'page count with a custom paginator' do
+    it 'returns the correct count' do
+      JSONAPI.configuration.default_paginator = :custom_offset
+
+      get :index, params: { page: { limit: 2, offset: 1 } }
+
+      expect(json.dig('meta', 'page_count')).to eq(2)
+    end
+  end
+
+  describe 'using default limit param' do
+    it 'returns the correct count' do
+      JSONAPI.configuration.default_paginator = :offset
+
+      get :index, params: { page: {  offset: 1 } }
+
+      expect(json.dig('meta', 'page_count')).to eq(1)
+    end
+  end
+
+  describe 'using a custom page_count key' do
+    it 'returns the count with the correct key' do
+      JSONAPI.configuration.default_paginator = :paged
+      JSONAPI.configuration.top_level_meta_page_count_key = :total_pages
+
+      get :index, params: { page: { limit: 2, offset: 1 } }
+
+      expect(json.dig('meta', 'total_pages')).to eq(2)
+    end
+  end
+end

spec/jsonapi/utils/support/pagination_spec.rb

@@ -77,6 +77,43 @@
     end
   end
 
+  describe '#count_pages_for' do
+    shared_examples_for 'counting pages' do
+      it 'returns the correct page count' do
+        allow(subject).to receive(:page_params).and_return(page_params)
+        expect(subject.send(:page_count_for, record_count)).to eq(page_count)
+      end
+    end
+
+    context 'with paged paginator' do
+      let(:record_count) { 10 }
+      let(:page_count) { 2 }
+      let(:page_params) { { 'size' => 5 } }
+      it_behaves_like 'counting pages'
+    end
+
+    context 'with offset paginator' do
+      let(:record_count) { 10 }
+      let(:page_count) { 2 }
+      let(:page_params) { { 'limit' => 5 } }
+      it_behaves_like 'counting pages'
+    end
+
+    context 'with 0 records'  do
+      let(:record_count) { 0 }
+      let(:page_count) { 0 }
+      let(:page_params) { {} }
+      it_behaves_like 'counting pages'
+    end
+
+    context 'with no limit param' do
+      let(:record_count) { 10 }
+      let(:page_count) { 1 }
+      let(:page_params) { {} }
+      it_behaves_like 'counting pages'
+    end
+  end
+
   describe '#count_records_from_database' do
     shared_examples_for 'skipping eager load SQL when counting records' do
       it 'skips any eager load for the SQL count query (default)' do

spec/test_app.rb

@@ -16,6 +16,9 @@
 
   config.top_level_meta_include_record_count = true
   config.top_level_meta_record_count_key = :record_count
+
+  config.top_level_meta_include_page_count = true
+  config.top_level_meta_page_count_key = :page_count
 end
 
 ##